6 ms·

SOBA: Potential blood test for Alzheimer's disease

161 points by WaitWaitWha 4y ago

bugbuddy 4y ago
IMHO Alzheimer’s disease is not a single disease but rather a collection of diseases that exhibit similar symptoms and pathologies. I based this opinion on years of observations of old people I know.
- vidarh 4y ago
  Dementia is a syndrome. Alzheimer's is just one form of dementia. Unless you knew the specific diagnosis of the old people you've observed you might just have observed people with different forms of dementia. It's possible Alzheimer's itself will turn out to be a syndrome, but if so it still forms a very specific subset of dementia.
aardvarkr 4y ago
Sounds amazing, though I don’t know how long it takes for something to go from the “medical research” stage to “a test your doctor can order” stage, and I’m afraid that will be >10 years
- whatshisface 4y ago
  The likelihood of hurting the patient weighs in on how hard it is to get something approved, and blood tests are much less likely to hurt somebody than a lot of other things.
  - xattt 4y ago
    Especially with something not quite actionable, like routine PSA testing or back pain, physicians have been historically trained to withhold on testing in the interest of cost-savings and patient anxiety. However, with medical assistance in dying coming on line, at least in Canada, the “actionable” part may be pre-planning.
    - Salgat 4y ago
      If anything, it can give a lot more data on how Alzheimers develops over the years.
    - joshspankit 4y ago
      I’d love to see a future where we test “excessively”. A CT/Ultrasound when someone walks in to emerg, bloodwork for things that are just possibilities, and so-on. The value in catching things early and in having a timeline to look back on is probably massive.
      - danielheath 4y ago
        Tests have a false positive rate. Real suffering is caused by increasing the number of false positives (by increasing testing).
        mchusma 4y ago
        I've heard this argument often, and it's never articulated correctly. (1) False positives if handled poorly cause suffering. (2) There is problem where we hide the statistics in an attempt to make things more relatable. Tests are often not "positive" or "negative", they just mean something like "given your situation, you have an x% chance of having this issue". Conveying the information more accurately and responding correctly fix most problems. Cancers and some other diseases are almost entirely preventable if fixed early enough, which require more testing with more false positives and this is absolutely worth the tradeoff for most people. Ultimately, we should give patients the information and choice whether to test or not.
        vidarh 4y ago
        False positives, or even the screening itself, if at a large enough scale, causes death. E.g. I had a gastroscopy recently. Endoscopies (e.g. for gastroscopy, colonoscopy) have incidence rates in the 0.1%-1% range. Most incidents are minor. Minor bleeds etc. Some are major. Perforation is a risk. Some performation leads to death. Over-prescribe endoscopies either as a first test or as a followup and you'll be killing more people than you save, even if the risk to any individual patient is tiny. It might seem worth it. E.g. you might catch a prostate cancer early from a colonoscopy. You might catch a hernia that could become a problem from a gastroscopy. Or any number of other things. The problem is that broaden screening too much, and your true positive rate becomes too low, and the true positive rate where the problem would otherwise go undetected and cause problems becomes even lower, and so for many conditions routine screening barely budges survival rates for true positives, but creates a mortality rate for false positives. Sometimes broadening testing is worth it - a serious enough and frequent enough condition can warrant it by saving more than it kills even if you only marginally improve survival rates, or you might have a condition that is rare but where detection can very significantly affect survival rates. But often it isn't. E.g. too broad screening for prostate cancer and breast cancer are both cases where the benefit in terms of nudging survival rates from broad screening vs. more targeted efforts (e.g. screening people who have felt something) is low enough that the advice most places is to focus on limited age groups or other risk factors. Hernias - I turned out to have one - is another one where the proportion that ever becomes a serious problem is so limited that the (tiny) risk of more broadly using gastroscopy to look specifically for that (rather than to investigate potentially more serious problems) is rarely warranted, and where the risk of a portion of patients pushing and getting (a lot more risky) surgical intervention in cases where it is not medically necessary is another reason to discourage too broad screening. There's a continuum here from not allowing patients to choose, via allowing it but discouraging it, to actively encouraging it, to broad screening programs. There are a whole lot of things that'd be fine to allow if a patient has specific fears, that still should be broadly discouraged.
- deleted 4y ago
  [deleted]
ddouglascarr 4y ago
Any one else read this as “presidential blood test for alzheimers”?
- epicureanideal 4y ago
  No need for a test in his case.
chimineycricket 4y ago
Does this mean that Alzheimer's is something that floats around your body? Or signs of it floating around? I always assumed it was something that could develop in anyone, like heart disease or some liver problem (except on the brain).
- carbocation 4y ago
  Heart disease risk is strongly influenced by "floating" factors (e.g., apolipoprotein B containing particles). A risk factor for Alzheimer's disease is your ApoE allele, so it's not particularly odd to me that circulating factors could influence risk. But even if not—even if the test is just picking up on incidentally released factors that are just detectable—it could be sensible. (I'm saying this completely agnostic to the claims of the article itself, just replying to your comment with general ideas.)
- lstamour 4y ago
  I can’t claim to know much about this, but as someone who recently suffered from possibly temporary amyloidosis-like symptoms, I’ve had to research this a lot recently. Basically, amyloids have been known for centuries as e.g. white stuff that collects in spleens and recently research on dementia has turned to amyloids as one of the precursors of one of the types of Alzheimer’s. It’s not yet clear if every case has amyloid involvement or if clearing amyloids can resolve the condition without any side effects yet, in particular there’s been reported brain shrinkage. https://en.m.wikipedia.org/wiki/Amyloid_beta https://en.m.wikipedia.org/wiki/Amyloid_beta talks about the thing floating around your body in more detail. I can’t say I’m an expert at any of this though. I’ve mostly looked at this from an AA amyloidosis perspective rather than an Altzheimer’s one. We actually already have a test for the presence of amyloids - SAA blood tests commonly used to diagnose infection in horses and cats. Other creatures, including humans, can also measure C Reactive Protein, but both CRP and SAA are measures of stress or inflammation associated with bacterial infection. Your body routinely gets rid of amyloids it might produce, which is part of why it’s said people with AA amyloidosis recover when the underlying cause is treated, I think. But it’s unclear how well we can recover long-term and amyloids and biofilms are still active research areas. All I can say is that for my amyloidosis-like symptoms, taking vitamin C regularly helps my thinking and the occasional high dose of vitamin A appears to temporarily reverse some of the amyloid-induced nerve damage. But I should also clarify I’m still awaiting test results to determine if I have amyloids and also my condition improves with antibiotics which means vitamin A and C might be interfering with bacteria (where biofilm = amyloids) rather than with the amyloid fibrils on their own.
dzink 4y ago
The big question is would you want to know of you have Alzheimer’s early at this point? Is there reliable treatment or cure? Those would be easier to develop if a reliable test is invented, but without them, would an adult likely only gain the loss of agency of their life? What would you do to prepare you and loved ones for losing yourself? What would your remaining life change into, by knowing? What would your loved and not so loved ones do if they knew?
- mostlysentient 4y ago
  I would prefer early awareness just so I can be more attentive to potential early warnings signs. Though, this only makes sense if you have some degree of optimism that there will be more effective treatments available by the time genetics catch up with you.
- jacobsenscott 4y ago
  I would use the time to get my finances in order - which essentially means moving as many of my assets as possible out of reach of the predatory nursing home and memory care industry. I would try and find a way transfer all my assets to my children and/or spouse, and ensure they would never list me as a dependent anywhere. I'm not clear if the nursing home can take your spouse's assets or not. If so we would need to file for divorce to protect her assets. I would essentially go broke and let medicade pay for my care. Sure they don't put you in in the "finest" facility, but pretty soon you'll be far enough gone it won't matter. The expensive places are just widow dressing anyway. You are treated the same everywhere.
  - wil421 4y ago
    You have a very dark view. As someone who has put a few family members through nursing homes and hospice my experience was very pleasant. Nobody was after their money. No one was trying to rip them off. The hospice care was kind and supportive. Why do have some idea that a nursing home is going take you money? I’ve never heard of these situations outside of Reddit.
    - 4y ago
netik 4y ago
doesn’t this still support the amyloid hypothesis? i hear there’s many different theories for Alzheimer’s now
- zackees 4y ago
  [dead]

161 points by WaitWaitWha 4y ago

IMHO Alzheimer’s disease is not a single disease but rather a collection of diseases that exhibit similar symptoms and pathologies. I based this opinion on years of observations of old people I know.

vidarh 4y ago
Dementia is a syndrome. Alzheimer's is just one form of dementia. Unless you knew the specific diagnosis of the old people you've observed you might just have observed people with different forms of dementia. It's possible Alzheimer's itself will turn out to be a syndrome, but if so it still forms a very specific subset of dementia.

aardvarkr 4y ago

Sounds amazing, though I don’t know how long it takes for something to go from the “medical research” stage to “a test your doctor can order” stage, and I’m afraid that will be >10 years

whatshisface 4y ago
The likelihood of hurting the patient weighs in on how hard it is to get something approved, and blood tests are much less likely to hurt somebody than a lot of other things.
- xattt 4y ago
  Especially with something not quite actionable, like routine PSA testing or back pain, physicians have been historically trained to withhold on testing in the interest of cost-savings and patient anxiety. However, with medical assistance in dying coming on line, at least in Canada, the “actionable” part may be pre-planning.
  - Salgat 4y ago
    If anything, it can give a lot more data on how Alzheimers develops over the years.
  - joshspankit 4y ago
    I’d love to see a future where we test “excessively”. A CT/Ultrasound when someone walks in to emerg, bloodwork for things that are just possibilities, and so-on. The value in catching things early and in having a timeline to look back on is probably massive.
    - danielheath 4y ago
      Tests have a false positive rate. Real suffering is caused by increasing the number of false positives (by increasing testing).
      - mchusma 4y ago
        I've heard this argument often, and it's never articulated correctly. (1) False positives if handled poorly cause suffering. (2) There is problem where we hide the statistics in an attempt to make things more relatable. Tests are often not "positive" or "negative", they just mean something like "given your situation, you have an x% chance of having this issue". Conveying the information more accurately and responding correctly fix most problems. Cancers and some other diseases are almost entirely preventable if fixed early enough, which require more testing with more false positives and this is absolutely worth the tradeoff for most people. Ultimately, we should give patients the information and choice whether to test or not.
        vidarh 4y ago
        False positives, or even the screening itself, if at a large enough scale, causes death. E.g. I had a gastroscopy recently. Endoscopies (e.g. for gastroscopy, colonoscopy) have incidence rates in the 0.1%-1% range. Most incidents are minor. Minor bleeds etc. Some are major. Perforation is a risk. Some performation leads to death. Over-prescribe endoscopies either as a first test or as a followup and you'll be killing more people than you save, even if the risk to any individual patient is tiny. It might seem worth it. E.g. you might catch a prostate cancer early from a colonoscopy. You might catch a hernia that could become a problem from a gastroscopy. Or any number of other things. The problem is that broaden screening too much, and your true positive rate becomes too low, and the true positive rate where the problem would otherwise go undetected and cause problems becomes even lower, and so for many conditions routine screening barely budges survival rates for true positives, but creates a mortality rate for false positives. Sometimes broadening testing is worth it - a serious enough and frequent enough condition can warrant it by saving more than it kills even if you only marginally improve survival rates, or you might have a condition that is rare but where detection can very significantly affect survival rates. But often it isn't. E.g. too broad screening for prostate cancer and breast cancer are both cases where the benefit in terms of nudging survival rates from broad screening vs. more targeted efforts (e.g. screening people who have felt something) is low enough that the advice most places is to focus on limited age groups or other risk factors. Hernias - I turned out to have one - is another one where the proportion that ever becomes a serious problem is so limited that the (tiny) risk of more broadly using gastroscopy to look specifically for that (rather than to investigate potentially more serious problems) is rarely warranted, and where the risk of a portion of patients pushing and getting (a lot more risky) surgical intervention in cases where it is not medically necessary is another reason to discourage too broad screening. There's a continuum here from not allowing patients to choose, via allowing it but discouraging it, to actively encouraging it, to broad screening programs. There are a whole lot of things that'd be fine to allow if a patient has specific fears, that still should be broadly discouraged.
deleted 4y ago
[deleted]

ddouglascarr 4y ago

Any one else read this as “presidential blood test for alzheimers”?

epicureanideal 4y ago
No need for a test in his case.

chimineycricket 4y ago

Does this mean that Alzheimer's is something that floats around your body? Or signs of it floating around? I always assumed it was something that could develop in anyone, like heart disease or some liver problem (except on the brain).

carbocation 4y ago
Heart disease risk is strongly influenced by "floating" factors (e.g., apolipoprotein B containing particles). A risk factor for Alzheimer's disease is your ApoE allele, so it's not particularly odd to me that circulating factors could influence risk. But even if not—even if the test is just picking up on incidentally released factors that are just detectable—it could be sensible. (I'm saying this completely agnostic to the claims of the article itself, just replying to your comment with general ideas.)
lstamour 4y ago
I can’t claim to know much about this, but as someone who recently suffered from possibly temporary amyloidosis-like symptoms, I’ve had to research this a lot recently. Basically, amyloids have been known for centuries as e.g. white stuff that collects in spleens and recently research on dementia has turned to amyloids as one of the precursors of one of the types of Alzheimer’s. It’s not yet clear if every case has amyloid involvement or if clearing amyloids can resolve the condition without any side effects yet, in particular there’s been reported brain shrinkage. https://en.m.wikipedia.org/wiki/Amyloid_beta https://en.m.wikipedia.org/wiki/Amyloid_beta talks about the thing floating around your body in more detail. I can’t say I’m an expert at any of this though. I’ve mostly looked at this from an AA amyloidosis perspective rather than an Altzheimer’s one. We actually already have a test for the presence of amyloids - SAA blood tests commonly used to diagnose infection in horses and cats. Other creatures, including humans, can also measure C Reactive Protein, but both CRP and SAA are measures of stress or inflammation associated with bacterial infection. Your body routinely gets rid of amyloids it might produce, which is part of why it’s said people with AA amyloidosis recover when the underlying cause is treated, I think. But it’s unclear how well we can recover long-term and amyloids and biofilms are still active research areas. All I can say is that for my amyloidosis-like symptoms, taking vitamin C regularly helps my thinking and the occasional high dose of vitamin A appears to temporarily reverse some of the amyloid-induced nerve damage. But I should also clarify I’m still awaiting test results to determine if I have amyloids and also my condition improves with antibiotics which means vitamin A and C might be interfering with bacteria (where biofilm = amyloids) rather than with the amyloid fibrils on their own.

dzink 4y ago

The big question is would you want to know of you have Alzheimer’s early at this point? Is there reliable treatment or cure? Those would be easier to develop if a reliable test is invented, but without them, would an adult likely only gain the loss of agency of their life? What would you do to prepare you and loved ones for losing yourself? What would your remaining life change into, by knowing? What would your loved and not so loved ones do if they knew?

mostlysentient 4y ago
I would prefer early awareness just so I can be more attentive to potential early warnings signs. Though, this only makes sense if you have some degree of optimism that there will be more effective treatments available by the time genetics catch up with you.
jacobsenscott 4y ago
I would use the time to get my finances in order - which essentially means moving as many of my assets as possible out of reach of the predatory nursing home and memory care industry. I would try and find a way transfer all my assets to my children and/or spouse, and ensure they would never list me as a dependent anywhere. I'm not clear if the nursing home can take your spouse's assets or not. If so we would need to file for divorce to protect her assets. I would essentially go broke and let medicade pay for my care. Sure they don't put you in in the "finest" facility, but pretty soon you'll be far enough gone it won't matter. The expensive places are just widow dressing anyway. You are treated the same everywhere.
- wil421 4y ago
  You have a very dark view. As someone who has put a few family members through nursing homes and hospice my experience was very pleasant. Nobody was after their money. No one was trying to rip them off. The hospice care was kind and supportive. Why do have some idea that a nursing home is going take you money? I’ve never heard of these situations outside of Reddit.
  - 4y ago

netik 4y ago

doesn’t this still support the amyloid hypothesis? i hear there’s many different theories for Alzheimer’s now

zackees 4y ago
[dead]